import React, {Component} from 'react';

class Demo extends Component {

    state = {count: 0};

    add = () => {
        //对象式的setState
        // //1、获取原来的count值
        // const {count} = this.state;
        // // 2、更新状态
        // this.setState({count: count + 1}, () => {
        //     console.log('回调中的count', this.state.count)
        // })
        // console.log(this.state.count) // 0

        //函数式的setState
        this.setState((state, props) => {
            return {count: state.count + 1}
        }, () => {
            console.log(this.state.count)
        });
    }

    render() {
        return (
            <div>
                <h1>当前求和为{this.state.count}</h1>
                <button onClick={this.add}>点我+1</button>
            </div>
        );
    }
}

export default Demo;